On Fri, Jul 08, 2011 at 05:58:02PM +0800, Yi Yang wrote:> I know I can set the default subvolume for a btrfs fs using > > sudo btrfs subvolume set-default 256 /btrfs/mnt > > But after that, how can get the default subvolume name? In my opinion, > btrfs-progs should provide "btrfs subvolume get-default /btrfs/mnm" to get > the default subvolume id and name, I think it is very easy to do this in > btrfs-progs and btrfs kernel space.I don''t think the current btrfs-progs will do it. As you pointed out though, it''s pretty easy to write the code to get the information (I implemented it for btrfs-gui without any additional kernel code, for example). We just need someone to implement it. :) I''d do it myself, but there''s about a dozen things higher up my priority list right now. Hugo. -- === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk == PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- Welcome to Rivendell, Mr Anderson... ---
Hi, I know I can set the default subvolume for a btrfs fs using sudo btrfs subvolume set-default 256 /btrfs/mnt But after that, how can get the default subvolume name? In my opinion, btrfs-progs should provide "btrfs subvolume get-default /btrfs/mnm" to get the default subvolume id and name, I think it is very easy to do this in btrfs-progs and btrfs kernel space. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 08.07.2011 11:58, Hugo Mills wrote:> On Fri, Jul 08, 2011 at 05:58:02PM +0800, Yi Yang wrote: >> I know I can set the default subvolume for a btrfs fs using >> >> sudo btrfs subvolume set-default 256 /btrfs/mnt >> >> But after that, how can get the default subvolume name? In my opinion, >> btrfs-progs should provide "btrfs subvolume get-default /btrfs/mnm" toget>> the default subvolume id and name, I think it is very easy to do this in >> btrfs-progs and btrfs kernel space. > > I don''t think the current btrfs-progs will do it. As you pointed > out though, it''s pretty easy to write the code to get the information > (I implemented it for btrfs-gui without any additional kernel code, > for example). We just need someone to implement it. :) > > I''d do it myself, but there''s about a dozen things higher up my > priority list right now. >Well, I''d be happy to try it. If it''s fine, I will try to follow the implementation from btrfs-gui. Andreas -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQIcBAEBAgAGBQJOFtWBAAoJEJIcBJ3+Xkgi/loP/jBB2BnrDvdRrN+gxP5XcCr8 62ZgP2XxO/MrIH5Xc4iNfUlMF8Fnttjr8LvjpbP3Q2Vfb2ogPPf6ALpBxtCOhaHJ yAFE4CvGon7f2sTGZO2EJxf4eSSoFUd19je+knPZOdyIDhc1lhXVp4LBeoPKySRe GDBQtv1uqYx79hD24R5vU5uK1xMDTVE5HHCy8jZtoaVGU4YO87u7vFfNJKqAmS/W tZbT3wkrod/HHo8sxS4ZKzPx1c0Ph/F3g/P8SWSHW5dmK/dSadRVe+Io09tyd6uu GfGMMtEs6lVjHq/gn4ebDZwk3pFmCACnCxk6cE5imGWOIvftLMCFRZkFS41BVn7s pAz+JEp7NaICKo3rbFlEZdvteBB0AaJTCeo2wAP0xD6aBEdT5MhxHZQCGi6PeRDn 2GTqw2gT+urTVa7Rr6O2PIQlC0mjFit6dVYcFzPIP/X+cXozDnuNeUmPD10VlEjN PHIOJjNX3Zod8KknQc/NX0kn3TcHZptX0EWJhtnC0X4kHMxZOUrfnlIMTjCP23pX TA4Zjc68fe5mDm75PnbT6h4QoLa5h3j8TWf8fYYFBC/FOcb4NFm4iJEA6AG7CS1l MExGgd619NWUXHDpjjhTTzerBHF+1D5XPNc0lnb7WNkjzfBQD5JfkFzCp3lzTylU dpaD5umGdM+1DlrD8NP/ =vM5/ -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
That''s great, can you share your source code with me? I''m very eager to get this now :-) -----Original Message----- From: Hugo Mills [mailto:hugo@carfax.org.uk] Sent: Friday, July 08, 2011 5:58 PM To: Yang, Yi Y Cc: linux-btrfs@vger.kernel.org Subject: Re: How to get the default subvolume? On Fri, Jul 08, 2011 at 05:58:02PM +0800, Yi Yang wrote:> I know I can set the default subvolume for a btrfs fs using > > sudo btrfs subvolume set-default 256 /btrfs/mnt > > But after that, how can get the default subvolume name? In my opinion, > btrfs-progs should provide "btrfs subvolume get-default /btrfs/mnm" to > get the default subvolume id and name, I think it is very easy to do > this in btrfs-progs and btrfs kernel space.I don''t think the current btrfs-progs will do it. As you pointed out though, it''s pretty easy to write the code to get the information (I implemented it for btrfs-gui without any additional kernel code, for example). We just need someone to implement it. :) I''d do it myself, but there''s about a dozen things higher up my priority list right now. Hugo. -- === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk == PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- Welcome to Rivendell, Mr Anderson... --- -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Jul 08, 2011 at 06:06:02PM +0800, Yang, Yi Y wrote:> That''s great, can you share your source code with me? I''m very eager to get this now :-)http://carfax.org.uk/btrfs-gui http://git.darksatanic.net/repo/btrfs-gui.git/ You probably want the btrfsgui.hlp.subvol.sv_list() function. Hugo.> -----Original Message----- > From: Hugo Mills [mailto:hugo@carfax.org.uk] > Sent: Friday, July 08, 2011 5:58 PM > To: Yang, Yi Y > Cc: linux-btrfs@vger.kernel.org > Subject: Re: How to get the default subvolume? > > On Fri, Jul 08, 2011 at 05:58:02PM +0800, Yi Yang wrote: > > I know I can set the default subvolume for a btrfs fs using > > > > sudo btrfs subvolume set-default 256 /btrfs/mnt > > > > But after that, how can get the default subvolume name? In my opinion, > > btrfs-progs should provide "btrfs subvolume get-default /btrfs/mnm" to > > get the default subvolume id and name, I think it is very easy to do > > this in btrfs-progs and btrfs kernel space. > > I don''t think the current btrfs-progs will do it. As you pointed out though, it''s pretty easy to write the code to get the information (I implemented it for btrfs-gui without any additional kernel code, for example). We just need someone to implement it. :) > > I''d do it myself, but there''s about a dozen things higher up my priority list right now. > > Hugo. >-- === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk == PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- vi: The core of evil. ---
From your source, you defined some structures using python and use them to get and parse btrfs metadata, very advanced and complicated :-), do you know there is any library to provide similar APIs in order that I can use some advanced APIs and don''t need to worry about frequent changes of btrfs superblock and other metadata. -----Original Message----- From: linux-btrfs-owner@vger.kernel.org [mailto:linux-btrfs-owner@vger.kernel.org] On Behalf Of Hugo Mills Sent: Friday, July 08, 2011 6:13 PM To: Yang, Yi Y Cc: linux-btrfs@vger.kernel.org Subject: Re: How to get the default subvolume? On Fri, Jul 08, 2011 at 06:06:02PM +0800, Yang, Yi Y wrote:> That''s great, can you share your source code with me? I''m very eager > to get this now :-)http://carfax.org.uk/btrfs-gui http://git.darksatanic.net/repo/btrfs-gui.git/ You probably want the btrfsgui.hlp.subvol.sv_list() function. Hugo.> -----Original Message----- > From: Hugo Mills [mailto:hugo@carfax.org.uk] > Sent: Friday, July 08, 2011 5:58 PM > To: Yang, Yi Y > Cc: linux-btrfs@vger.kernel.org > Subject: Re: How to get the default subvolume? > > On Fri, Jul 08, 2011 at 05:58:02PM +0800, Yi Yang wrote: > > I know I can set the default subvolume for a btrfs fs using > > > > sudo btrfs subvolume set-default 256 /btrfs/mnt > > > > But after that, how can get the default subvolume name? In my > > opinion, btrfs-progs should provide "btrfs subvolume get-default > > /btrfs/mnm" to get the default subvolume id and name, I think it is > > very easy to do this in btrfs-progs and btrfs kernel space. > > I don''t think the current btrfs-progs will do it. As you pointed > out though, it''s pretty easy to write the code to get the information > (I implemented it for btrfs-gui without any additional kernel code, > for example). We just need someone to implement it. :) > > I''d do it myself, but there''s about a dozen things higher up my priority list right now. > > Hugo. >-- === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk == PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- vi: The core of evil. --- -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Jul 08, 2011 at 06:28:54PM +0800, Yang, Yi Y wrote:> From your source, you defined some structures using python and use > them to get and parse btrfs metadata, very advanced and complicated > :-), do you know there is any library to provide similar APIs in > order that I can use some advanced APIs and don''t need to worry > about frequent changes of btrfs superblock and other metadata.The fundamental btrfs data structures (which you''ll find defined in ctree.h in the btrfs-progs source, and which are mirrored in my python code) won''t change much, since they define the on-disk layout. Changing those structures creates incompatible filesystems, which is a Bad Thing, so it doesn''t happen all that often. Hugo. PS. On most development mailing lists, it''s conventional to write your replies below the text you''re replying to, not above.> -----Original Message----- > From: linux-btrfs-owner@vger.kernel.org [mailto:linux-btrfs-owner@vger.kernel.org] On Behalf Of Hugo Mills > Sent: Friday, July 08, 2011 6:13 PM > To: Yang, Yi Y > Cc: linux-btrfs@vger.kernel.org > Subject: Re: How to get the default subvolume? > > On Fri, Jul 08, 2011 at 06:06:02PM +0800, Yang, Yi Y wrote: > > That''s great, can you share your source code with me? I''m very eager > > to get this now :-) > > http://carfax.org.uk/btrfs-gui > http://git.darksatanic.net/repo/btrfs-gui.git/ > > You probably want the btrfsgui.hlp.subvol.sv_list() function. > > Hugo. > > > -----Original Message----- > > From: Hugo Mills [mailto:hugo@carfax.org.uk] > > Sent: Friday, July 08, 2011 5:58 PM > > To: Yang, Yi Y > > Cc: linux-btrfs@vger.kernel.org > > Subject: Re: How to get the default subvolume? > > > > On Fri, Jul 08, 2011 at 05:58:02PM +0800, Yi Yang wrote: > > > I know I can set the default subvolume for a btrfs fs using > > > > > > sudo btrfs subvolume set-default 256 /btrfs/mnt > > > > > > But after that, how can get the default subvolume name? In my > > > opinion, btrfs-progs should provide "btrfs subvolume get-default > > > /btrfs/mnm" to get the default subvolume id and name, I think it is > > > very easy to do this in btrfs-progs and btrfs kernel space. > > > > I don''t think the current btrfs-progs will do it. As you pointed > > out though, it''s pretty easy to write the code to get the information > > (I implemented it for btrfs-gui without any additional kernel code, > > for example). We just need someone to implement it. :) > > > > I''d do it myself, but there''s about a dozen things higher up my priority list right now. > > > > Hugo. > > >-- === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk == PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- vi: The core of evil. ---